Pour oil into a heavy medium pan and set over medium-high heat. When hot, put in shrimp and stir them around for 2 to 3 minutes or until just opaque. Remove with a slotted spoon and put in a bowl. Turn off heat. Add lemon juice and cilantro to bowl of shrimp. Stir to mix and taste for balance of seasonings.

Put cardamom and chicken stock into pan used for cooking the shrimp and bring to a boil, scraping bottom to release the seasonings. Add drained rice, 1/2 teaspoon salt if the stock is salted and 1 teaspoon if it is not, and bring to a boil again.

Cover tightly, turn heat to very, very low, and cook 25 minutes. Put shrimp and accumulated juices over top of rice, cover quickly and keep cooking another minute. Turn off heat. Stir gently to mix and keep covered until needed. Remove cardamom pods before serving.